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  <div id="layout-content"><div id="function.fdatasync" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">fdatasync</h1>
  <p class="verinfo">(PHP 8 &gt;= 8.1.0)</p><p class="refpurpose"><span class="refname">fdatasync</span> &mdash; <span class="dc-title">Synchronizes data (but not meta-data) to the file</span></p>

 </div>
 
 <div class="refsect1 description" id="refsect1-function.fdatasync-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>fdatasync</strong></span>(<span class="methodparam"><span class="type">resource</span> <code class="parameter">$stream</code></span>): <span class="type">bool</span></div>

  <p class="para rdfs-comment">
   This function synchronizes <code class="parameter">stream</code> contents to storage media, just like <span class="function"><a href="function.fsync.html" class="function">fsync()</a></span> does,
   but it does not synchronize file meta-data.
   Note that this function is only effectively different in POSIX systems.
   In Windows, this function is aliased to <span class="function"><a href="function.fsync.html" class="function">fsync()</a></span>.
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-function.fdatasync-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>
    
     <dt>
<code class="parameter">stream</code></dt>

     <dd>

      <p class="para">文件指针必须是有效的，必须指向由
<span class="function"><a href="function.fopen.html" class="function">fopen()</a></span> 或 <span class="function"><a href="function.fsockopen.html" class="function">fsockopen()</a></span> 成功打开的文件(并还未由 <span class="function"><a href="function.fclose.html" class="function">fclose()</a></span> 关闭)。</p>
     </dd>

    
   </dl>

  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.fdatasync-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   成功时返回 <strong><code>true</code></strong>， 或者在失败时返回 <strong><code>false</code></strong>。
  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-function.fdatasync-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-2147">
    <p><strong>示例 #1 <span class="function"><strong>fdatasync()</strong></span> example</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /><br />$file&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">'test.txt'</span><span style="color: #007700">;<br /><br /></span><span style="color: #0000BB">$stream&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">fopen</span><span style="color: #007700">(</span><span style="color: #0000BB">$file</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">'w'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">fwrite</span><span style="color: #007700">(</span><span style="color: #0000BB">$stream</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">'test&nbsp;data'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">fwrite</span><span style="color: #007700">(</span><span style="color: #0000BB">$stream</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"\r\n"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">fwrite</span><span style="color: #007700">(</span><span style="color: #0000BB">$stream</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">'additional&nbsp;data'</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">fdatasync</span><span style="color: #007700">(</span><span style="color: #0000BB">$stream</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">fclose</span><span style="color: #007700">(</span><span style="color: #0000BB">$stream</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
    </div>

   </div>
  </p>
 </div>

 
 <div class="refsect1 seealso" id="refsect1-function.fdatasync-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="function.fflush.html" class="function" rel="rdfs-seeAlso">fflush()</a> - 将缓冲内容输出到文件</span></li>
    <li class="member"><span class="function"><a href="function.fsync.html" class="function" rel="rdfs-seeAlso">fsync()</a> - Synchronizes changes to the file (including meta-data)</span></li>
   </ul>
  </p>
 </div>


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